/*
 * Copyright (c) 2011-2012 Alexander Dubu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * o  Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * o  Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * o  Neither the name Axil nor the names of its contributors may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

package axil.etc;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

import static axil.framework.Functions.abort;
import static axil.framework.Functions.nv;


/**
 * A specialized collection type for objects that provide a unique identity.
 */
public class IdentityMap<T extends Identity>
	implements Iterable<T>, Compressed, Cloned {
	private HashMap<String,T> map;
	private ArrayList<T> list;


	public IdentityMap() {
		map = new HashMap<String,T>();
		list = new ArrayList<T>();
	}


	private IdentityMap(IdentityMap other) {
		this.map = (HashMap<String,T>)other.map.clone();
		this.list = (ArrayList<T>)other.list.clone();
	}


	public void put(T object) {
		if (contains(object)) {
			throw abort(
			    "An object with that identity has already been defined. " +
			    "Existing definitions cannot be overridden.",
			    nv("type", object.getClass().getSimpleName()),
			    nv("identity", object.identity()));
		}
		list.add(object);
		map.put(object.identity(), object);
	}


	public boolean contains(String ident) {
		return map.containsKey(ident);
	}


	public boolean contains(T object) {
		return map.containsKey(object.identity());
	}


	public T get(String ident) {
		return map.get(ident);
	}


	public List<T> values() {
		return list;
	}


	/**
	 * Clone this object, returning a new object. The clone is sufficiently
	 * deep to ensure that any modifications to the clone, or to any member of
	 * the clone, do not impact this object.
	 */
	public Object cloned() {
		return new IdentityMap(this);
	}


	/**
	 * Returns an iterator over a set of elements of type T.
	 */
	public Iterator<T> iterator() {
		return list.iterator();
	}


	/**
	 * Compress this object, reducing its memory footprint as much as possible.
	 * A compressed object is still fully functional for script evaluation but
	 * may no longer possess complete metadata.
	 */
	public void compress() {
		for (Object object : this) {
			((Compressed)object).compress();
		}
	}
}
